Knowing how to measure a garage door correctly makes a real difference in getting an accurate estimate — the two numbers that drive pricing most are width and height, and small measuring mistakes can shift a quote more than homeowners expect. Here's how to do it properly.
What to measure
- Width — measure the opening at its widest point, wall to wall, not the current door's outer frame
- Height — measure from the floor to the top of the opening, at the center, since floors aren't always perfectly level
- Headroom — the space above the opening up to the ceiling or nearest obstruction, needed for the track and spring system
- Side room — the space on each side of the opening, needed for the vertical tracks
- Backroom — the depth from the opening back into the garage, needed for the horizontal tracks and opener
Standard sizes vs. your actual opening
Most residential garages use fairly standard openings — commonly around 8 or 9 feet wide by 7 feet tall for a single door, and around 16 feet wide by 7 feet tall for a double. But older homes, especially in established Puget Sound neighborhoods, sometimes have nonstandard openings, so measuring your actual opening rather than assuming a standard size matters.
Common measuring mistakes
- Measuring the current door's panel size instead of the rough opening — these aren't always the same
- Only measuring at one point, missing that the opening isn't perfectly square or level
- Forgetting to check headroom, which matters more for openers and higher-lift track configurations
- Rounding measurements — even an inch or two of difference can matter for an exact, made-to-size door
Our wizard walks you through entering your width and height, and gives you an exact installed price in about two minutes — accurate enough to plan around, and confirmed precisely at the free inspection before anything is scheduled.